Backyard Aquaponics
A place to discuss aquaponics

Hi there,

Looking to size a climate battery / SHCS (subterranean heating and cooling system) but noticed that the calculator from Sunny John has gone missing (numsum no longer exists).

Does anyone have a copy? Or another sizing tool?

Thanks!

I've got some documents somewhere on modeling ground source heat pumps (which is what I think you are talking about) but their values would be different because of the different conditions in Australia.

Hi Stuart. Actually that's different. I'm talking about this.

Right. I looked at these a while ago. I seem to remember that there could be problems with mildew?

Looking at this plan I'm confused as to why they have gone with such a spaghetti arrangement. Why not have a manifold at either end of the greenhouse. Easier to install, less fans, more efficient distribution of pies and gear.

They explain in the details. Short runs use less fan power and get a larger temp. drop per ft. of run.

Jer...

I'm going to read this again because it interests me but I wish they would just write about the technology without the hippy tree huggin invective. Makes my eyes glaze in a rain bow swirl

Did I mention I wasn't having a good day?

Re spaghetti.

I've re read the web page and its links. Glad I did because it reminded me of a lot of things but the spaghetti design is inefficient in so many ways.

Its all about the physics. The fluid flows (air is a fluid) and the heat transfer.

The website says several times to keep the flow of air through individual pipes even, this is basic manifold design. Much easier to do this with a grid layout rather than a spaghetti layout.

The amount of power the system takes to run is due to the friction losses in the pipes. Since air of one mass is being replaced with air of another mass the only real expenditure of energy is overcoming the back pressure which is caused by the friction otherwise known as air resistance.

The other thing to design is the air speed and the residence time if having a manifold at either end of the house means the pipe runs are tool long you could run a manifold either side or break up the runs with extra manifolds.

Any idea where I could find some calcs that could tell me how to size it and what kind of heat savings to expect? I'm an engineer but I've never looked into condensation rates.

Well there is basic info to size the systems on the website and that is probably as good as you are going to get for free.

Does the guy answer emails still?

If you use the guidelines on the website to get the total length of pipe you need you can use standard fluid dynamic theory to design the layout and manifolds. The fan you would ideally spec after you have designed the pipe network.

I'm pretty sure someone on the forum built their greenhouse with one of these systems in the floor

Anyone remember who that was? It was one of those off center gable greenhouses (big sloping windows on the sun side insulated wall on the shade side. I remember seeing a photo of lots o drainage coil in the floor which was covered by gravel.

Stuart, the thread search god has arrived at your service..

viewtopic.php?f=18&t=21897

Ten points Charlie.

Might find some additional info on Web4Deb's thread, he (Rob) used the ground pipes/earth tubes to store heat in his greenhouse.